The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
Free tracker included with every download this week
Running Weight Loss Before and After — Evidence & UK Options
Running is one of the most effective forms of cardiovascular exercise for weight loss, but results depend on consistency, diet, and your starting point. Before and after running transformations often show significant improvements in weight management, fitness, and health markers. In the UK, you can combine running with prescription weight management options if you're eligible. This guide covers what the evidence shows, how to get started, and UK-licensed medication options available to support your weight loss journey.
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Calculate Your BMI Instantly
Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Weight Loss Through Running: What Evidence Shows
Running burns significant calories — typically 400–600 kcal per hour depending on pace, body weight, and fitness level. For weight loss to occur, you need a calorie deficit of around 500 kcal per day, which translates to approximately 0.5 kg (1.1 lbs) per week. Running alone can achieve this, but combining it with dietary changes typically produces better, more sustainable results.
- Moderate running (4–5 times weekly) combined with a balanced diet can produce 5–clinically studied weight loss over 12 weeks
- High-intensity interval training (HIIT) running sessions may increase calorie burn and preserve muscle during weight loss
- Consistency matters more than intensity — regular moderate running beats sporadic intense sessions
The NHS recommends at least 150 minutes of moderate-intensity aerobic activity weekly, which running easily provides. Check your BMI to understand your starting point, and use our free BMI calculator to track changes as you progress.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
UK Prescription Weight Management Options
If you're carrying excess weight and eligible for prescription support, GLP-1 medications are available in the UK to support weight loss alongside exercise and diet. These prescription-only medicines work by reducing appetite and helping you feel fuller, making it easier to maintain the calorie deficit needed for weight loss.
- Mounjaro (tirzepatide) — dual GIP/GLP-1 agonist, once-weekly injection, average 15–clinically studied weight loss in clinical trials
- Wegovy (semaglutide) — GLP-1 agonist, once-weekly injection, average 14–clinically studied weight loss in trials
- Eligibility: BMI 30+ or BMI 27+ with weight-related health conditions (type 2 diabetes, high blood pressure, cardiovascular disease)
Running paired with prescription medication can amplify results. Try our free GLP-1 weight loss calculator to explore potential outcomes with medication support.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Can you lose weight just by running without changing diet?
Running creates a calorie deficit, so weight loss is possible. However, diet has a huge impact on results. The NHS recommends combining exercise with healthy eating for sustainable weight loss of 0.5–1 kg per week. Without dietary changes, running progress may be slower. Most successful before-and-after transformations combine both approaches.
How long before you see before and after running weight loss results?
Initial changes often appear within 2–4 weeks (improved fitness, reduced bloating), but significant body composition changes typically take 8–12 weeks. The speed depends on starting weight, running frequency, diet, and genetics. Weighing yourself weekly and tracking progress with our free progress tracker helps you stay motivated through the process.
What's the difference between running and other cardio for weight loss?
Running burns more calories per unit time than walking but may be harder on joints. Cycling, swimming, and HIIT running all produce weight loss when creating a calorie deficit. The best exercise is the one you'll do consistently. Combining different cardio types prevents boredom and reduces injury risk.
Can I use prescription weight loss medication with running?
Yes. Prescription GLP-1 medications like Mounjaro and Wegovy are designed to be used alongside lifestyle changes including exercise. They don't replace running — they support it by reducing appetite, making it easier to maintain a calorie deficit. Always discuss exercise plans with your prescriber, especially if taking diabetes medication.
How do I find out if I'm eligible for UK prescription weight loss treatment?
Eligibility requires a BMI of 30 kg/m² or above, or BMI 27–29.9 with weight-related health conditions. Book an appointment with your GP to discuss. Alternatively, you can use our free BMI calculator to check your starting point, then speak to a healthcare professional about whether prescription support is right for you. NHS or private prescribing pathways are available.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.